New models for next generation wind turbines

Thursday December 22, 2016 13:40

In the last 20 years wind power capacity has been growing rapidly. Within a couple of years turbines became more efficient while costs relatively decreased. The ever-increasing size of the rotors is an important cause for the cost reduction. However, it becomes increasingly difficult to design such large turbines accurately and reliably because the aerodynamic models were developed for and validated on smaller turbines.

In a consortium of 13 international partners, ECN is developing and validating new models to design large rotors. “We’ve noticed that innovations violate assumptions in current tools. For example, airfoils for large wind turbines become thicker and there is lack of knowledge about the impact”, says Gerard Schepers, researcher at ECN. The AVATAR consortium brings existing aerodynamic and aeroelastic models to the urgently required next level. “Ready to be used in integral design codes for wind turbines up to 20 Megawatt.”

No time to lose ECN has been coordinating the AVATAR project that has been running since 2013. “We need to explore and understand new physics by conducting measurements and performing calculations with high-fidelity models. That knowledge is rapidly implemented into pragmatic tools, so that airfoils and blade tips can be designed with increased accuracy. Turbine manufacturers and farm owners have no time to lose”, says Schepers. Other consortium partners are working on advanced computational fluid dynamics (CFD) or testing facilities. “It’s good to see various countries, universities and industry partners working together side by side.”

Outdated versus future proof Although the AVATAR project is still continuing, the first results are clear. Schepers: “We have identified that current models, on aspects like so-called boundary layer transition, are not accurate enough to design next generation turbines. This is an important finding. New validated models are necessary to improve the aerodynamic predictions and decrease risks and costs.” The new models are tested on a virtual 10 MW wind turbine with a rotor that measures 207.8 meter. “Since innovations develop so quickly we expect it is possible to realise 20 MW turbines within a period of 10 years. All AVATAR partners, including ECN, are commited to enable these large innovations.”

For more information, please contact Gerard Scheepers or Peter Eecen via the contact form on our website.